1. Field of the Invention
An embodiment relates to a secondary battery and, more particularly, to a secondary battery capable of achieving more stable assembly of a polymer cell and a top case having an exterior shape that is irregular due to problems in a manufacturing process.
2. Discussion of Related Art
In general, a secondary battery is a battery in which conversion between chemical energy and electrical energy is reversible, such that charging and discharging can repetitively be performed. These batteries are increasingly used as a driving power supply for mobile and portable IT apparatuses as their weight decreases and their functionality increases.
The secondary battery includes a nickel-cadmium battery, a nickel-hydrogen battery, a nickel-zinc battery, a lithium secondary battery, etc. Among them, since the lithium secondary battery is rechargeable and can have a small size, be miniaturized, have a high capacity, high operating voltage and high energy density per unit weight, the lithium secondary battery is widely used in an advanced electronic apparatus fields. These batteries include a lithium-ion battery, a lithium-ion polymer battery a lithium polymer battery, etc.
One example is a polymer battery where a polymer cell is sealed in a case with an anode terminal and a cathode terminal from an electrode assembly exposed to the outside of the case. In addition, additional insulating tape is attached to outer surfaces of the anode and cathode terminals which are in contact with a sealed part when the anode and cathode terminals are exposed to the outside. This is also generally referred to as an insulating wing portion or an insulating terrace portion. However, the insulating wing portion or the insulating terrace portion that is formed by the insulating tape is frequently contracted and transformed due to heat when the polymer cell is sealed. In addition, when the insulating wing portion is deteriorated, size stability is deteriorated and it is difficult to provide a battery pack satisfying an overall outline dimensions of the cell. In particular, interference occurs when the cell is assembled with the top case due to the insulating wing portion which is deteriorated due to the heat, such that the overall size stability and reliability of the battery pack are reduced.